POS1053 PREVALENCE OF FIBROSING PROGRESSIVE INTERSTITIAL LUNG DISEASE IN RHEUMATOID ARTHRITIS PATIENTS
Authors: A. Manfredi, V. Venerito, M. Cazzato, S. Gentileschi, L. La Corte, A. M. Iuliano, G. Cassone, C. Vacchi, C. Tomassini, A. Rai, M. Lavista, D. Andrisani, E. Laurino, C. Canofari, E. Pedrollo, F. Atzeni, G. D. Sebastiani, B. Frediani, M. Mosca, F. Iannone, M. Sebastiani
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Interstitial lung disease (ILD) related to rheumatoid arthritis (RA) significantly impacts on quality of life and survival of the patients. Data about prevalence and natural history of RA-ILD are only partially known and mainly based on retrospective studies. The recent introduction of antifibrotic drugs have allowed for the first time the opportunity to treat ILD in RA patients; in fact, INBUILD study demonstrated the efficacy of nintedanib in the treatment of progressive fibrosing ILD different than idiopathic pulmonary fibrosis (IPF), including RA-ILD, but the prevalence of RA-ILD patients that may potentially benefit from nintedanib therapy remain unknown. <h3>Objectives</h3> Aim of the present multicenter Italian study was to investigate the prevalence of fibrosing progressive patterns in a cross-sectional cohort of non-selected RA-ILD patients. <h3>Methods</h3> We enrolled in the study all RA patients according to 2010 EULAR/ACR classification criteria, with an ILD confirmed at high resolution computed tomography (HRCT) and with a follow-up of at least 24 months. According to the current indication of nintedanib, patients were defined as having a progressive fibrosing ILD in case of a relative decline in forced vital capacity (FVC) ≥10% predicted and/or an increased extent of fibrotic changes on chest imaging in a 24 month-period. Respiratory symptoms were excluded to reduce possible bias due to the retrospective interpretation of cough and dyspnoea. <h3>Results</h3> One hundred and thirty-four RA-ILD patients were enrolled in the study (males/females 54/80, mean age 72±9.5 years, mean RA and ILD duration 13.1±9.5 and 4.6±4.1 years, respectively. Anticitrullinated peptides antibodies (ACPA) and rheumatoid factor (RF) were recorded in 76.2% and 87.6% of cases, respectively. According to radiologic features, ILD was classified as probable or definite usual interstitial pneumonia (UIP) in 50.7% of patients, NSIP in 19.4% and other patterns in 29.8%. A fibrosing pattern was reported in 73.9% of cases (all patients with UIP pattern, 57.7% of patients with NSIP and 40% with other pattern). A relative decline of 6.8% of forced vital capacity (FVC) was recorded during the follow-up, without significant difference between fibrosing and non-fibrosing ILD (6.3%±13.8 vs 5.9%±21.3, respectively). A relative FVC decline ≥ 10% and/or a progression of radiologic fibrotic involvement was observed in 38.8% of patients. As expected, a significant difference in relative decline of FVC was recorded between progressive and non-progressive ILD (15.7%±16.4 vs -1.3%±8.3, respectively). Globally, a fibrosing progressive pattern was recorded in 35.8% of patients (48/134, 48.5% of patients with fibrosing pattern). Of interest, also 11.4% of patients with a non-fibrosing pattern showed a progressive behavior of disease (see Figure 1). <h3>Conclusion</h3> The recent introduction of nintedanib for the treatment of fibrosing progressive ILD different by IPF has potentially changed the paradigm for the treatment of RA-ILD. In fact, for the first time, rheumatologist has a therapy available with efficacy on RA related lung involvement. This study shows some limitations. The retrospective design and the need of serial HRCT and FVC could induce an overestimation of progressive disease (pulmonary function could not have been properly evaluated in asymptomatic patients). On the other hand, the exclusion of symptoms, such as a worsening of dyspnea and cough, might underestimate the prevalence of progressive lung disease. Finally, some patients were already treated with antifibrotic drugs, possibly influencing the evolution of lung disease in the last 2 years. In conclusion, about a third of RA-ILD patients shows a fibrosing progressive pattern of ILD and might benefit of antifibrotic treatment, alone or in combination with anti-rheumatic drugs. For RA patients with progressive non-fibrosing ILD, we need more studies to establish the best therapeutic approach. <h3>References</h3> [1] Flaherty KR et al. N Engl J Med 2019;381:1718-1727 [2] Manfredi A, et al. Expert Rev Clin Immunol. 2021;17:485-97 <h3>Acknowledgements</h3> I have no acknowledgement to declare. <h3>Disclosure of Interests</h3> Andreina Manfredi Speakers bureau: BMS, Lilly, and. Boehringer-Ingelheim, Vincenzo Venerito: None declared, Massimiliano Cazzato: None declared, Stefano Gentileschi: None declared, Laura La Corte: None declared, Anna Maria Iuliano: None declared, Giulia Cassone: None declared, Caterina Vacchi: None declared, Caterina Tomassini: None declared, Alessandra Rai: None declared, Marlea Lavista: None declared, Dario Andrisani: None declared, Elenia Laurino: None declared, Claudia Canofari: None declared, elisa pedrollo: None declared, Fabiola Atzeni: None declared, Gian Domenico Sebastiani: None declared, Bruno Frediani: None declared, Marta Mosca: None declared, Florenzo Iannone: None declared, Marco Sebastiani Speakers bureau: BMS, Pfizer, and Boehringer-Ingelheim, Consultant of: Lilly, Grant/research support from: BMS, Pfizer.